The appearance and subsequent development of electronic products started only a few decades ago; however, the progressing speed of this industry has surpassed many others. This is especially so in the development of computer related periphery products and video-audio products. New products are ever emerging due to the needs of the working people and recreation needs of the general population. Much progress has been made in these areas; new products are ever emerging. Take the display product for instance; the conventionally used display is constituted of a Cathode Ray Tube (CRT), which usually has the following drawbacks:                1. Since the conventional display is not equipped with flat screen, it is often suffering from a phenomenon of image twisting during watching.        2. The conventional cathode ray tube has comparatively larger power consumption, that is, the cathode ray tube will consume a conceivable more electricity that, as the consequence, the display of cathode ray tube suffers from the phenomena of high temperature and heat.        3. The size of the conventional display is bulky since it is restricted by the size of the cathode ray tube therein, so that a certain larger space is required for storing and operating the conventional display.        
New generation of displays including liquid crystal display (LCD), and plasma display, etc, are developed by manufacturers in view of the aforementioned deficiencies of the conventional display. With the maturation of the LCD manufacturing technique, the price of the LCD is decreased to a degree almost equal to that of the conventional display of cathode ray tube. Since the LCD has the advantages of low radiation, low power consumption, small size, and larger visual angle, it is a favorite of mostly common users.
The LCD display nowadays is mostly being implemented as computer monitor, liquid crystal TV, and displaying device and other 3C electronic products, such as mobile phone, digital camera, etc. The LCD provides a widespread application. However, if LCD is applied to the liquid crystal TV in which the conversion of image signal is very fast and the image signal is continuous, a phenomenon of image sticking, as shown in FIG. 1, is generated and seen by human eyes. The happening of image sticking is because that the response time of the liquid crystal display is slower than the TV image signal. It is not easy to significantly improve the response time since it is confined by the properties of the liquid crystal material. In addition, the scan method of the conventional monitor is first to scan a screen horizontally and successively in a single direction, for example, the scanning is performed successively from the topmost end of the screen to the bottommost end of the screen. Next, a step of entirely erasing the image (discharging every pixel of the screen) is performed to black the screen entirely. Following that a scanning of the next image is performed. These steps are performed repeatedly to complete the displaying of liquid crystal display. Nevertheless, the conventional scan method still suffers the image-sticking phenomenon. In view of the above description, the present invention discloses an improved scan method for LCD monitor capable of efficiently eliminating the image-sticking phenomenon.